Within the US food system, which is one of the most notorious in the word, recent studies have show that up to 12,000 megatonnes of carbon dioxide are released into the atmosphere inequivalent a year, which translates to up to 86% of all food-related substances to be greenhouse gas emissions. This amounts to just over 1/3 of the entire greenhouse emissions that are produced by us on earth. This qwarfs the also staggering amount of carbon dioxide released by fossil fuels, which last year racked up to equaling a gargantuan 9.7 billion tonnes.
Nature.com released statistics to forward the idea that agriculture was more of a leading contributor of global warming than the fossil fuel industry: “Fertilizer manufacturing [is the next most common contributor], which releases up to 575 megatonnes, followed by refrigeration, which emits 490 megatonnes. The researchers found that the whole food system released 9,800–16,900 megatonnes of carbon dioxide equivalent into the atmosphere in 2008, including indirect emissions from deforestation and land-use changes.”
It has also been disclosed that the manufacturing of the equipment and substances that keep them working such as oils, and pesticides further increase the impact up to between 25% and 30% of the U.S.’s collective carbon footprint. (statistics via treehugger.com)